As per the International Health Regulations a country is obligated to notify WHO of any public health event that may constitute a Public Health Emergency of International Concern within 24 hours of assessment of public health information.

In its statement on February 1, 2016 WHO stated, “National authorities should ensure the rapid and timely reporting and sharing of information of public health importance relevant to this (Zika) Public Health Emergency of International Concern.

However, it was announced on November 16 that Zika is no longer a public health emergency but “Zika virus and associated consequences remain a significant enduring public health challenge requiring intense action” said WHO.

In November, 2016, first case of Zika was detected in India when a 34-year-old woman delivered a baby in BJ Medical College (BJMC) in Gujarat. In next three months two more cases were reported from the state. But instead of sharing the information with the public, the government concealed it.

The information was fully made public only on 15 May after the WHO announced that it had received reports about the virus from the Ministry of Health and Family Welfare.

Now taking the note of WHO categorising India as a site of active transmission of the Zika virus, the United States sent out an advisory, informing its citizens in India about the number of confirmed Zika infections in India.

The WHO, it noted, placed India as a ‘Category-2’ country for Zika risk. A Category-2, the second highest on a four-point scale and that also includes 2015 Zika-hotspot Brazil, indicates that the virus is being actively transmitted within the country.

The advisory clarified that the U.S. itself did not see its citizens in India at greater risk for contracting the mosquito-borne infection than from March 2017. It, however, maintains that pregnant women ought not to be travelling to the country. The British government has also advised pregnant women against travelling to India on account of the risk of the Zika virus.

Why India concealed its first cases of the Zika virus?

There has been shock among many public health professionals on why the public was not informed of the cases immediately after they were detected.

Rajib Dasgupta, a professor in the community medicine department at Delhi's Jawaharlal Nehru University, told BBC that this is unprecedented in India's public health history. “It is also disturbing and raises a lot of ethical issues, he told BBC.

Though the government had taken precautionary measure by beefing up 25 laboratories across the country since last year but when it came to the first cases, the government kept it a secret from people.

Interesting at the same time when the virus was first detected the Gujarat government was holding a major international business summit to woo investments. The local media reports the government didn’t want to create panic.

In its most recent outbreak, Zika, which is mainly a mosquito-borne disease, was identified in Brazil in 2015 and since then the infection has been linked to severe birth defects in almost 30 countries. Last year, 11 Southeast Asian countries - Brunei, Myanmar, Cambodia, Indonesia, Laos, Malaysia, Maldives, Philippines, Thailand, Timor-Leste and Vietnam were reported with outbreak of Zika infection in occasional or smaller level.

Also, Singapore was added to travel notice list. Such outbreak in other Asian countries made India vulnerable to Zika. Although, Zika is a mosquito-borne disease but Zika can also be sexually transmitted which raises alarms and indicate that it can be spread at a rapid rate. But is the government ready to deal with the challenge?